This invention relates to data cartridges, included but not limited to known QIC, QIC Wide, and Travan data cartridges. More particularly, this invention relates to mechanical, belt to roller tracking of data tapes in data cartridges. Still more particularly, this invention relates to an inverted crowning of the corner rolls in data cartridges to maintain positive belt tracking at high speed or low speed tracking conditions in the cartridge, while maintaining ease of manufacture.